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Rigoberto E. M. Morales

Bio: Rigoberto E. M. Morales is an academic researcher from Federal University of Technology - Paraná. The author has contributed to research in topics: Slug flow & Two-phase flow. The author has an hindex of 17, co-authored 138 publications receiving 1005 citations. Previous affiliations of Rigoberto E. M. Morales include Centro Federal de Educação Tecnológica de Minas Gerais.


Papers
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TL;DR: In this paper, a technique that automatically estimates bubble parameters (e.g., frequency, dimension and velocity) through video analysis of high-speed camera measurements in horizontal pipes is presented.

67 citations

Journal ArticleDOI
TL;DR: In this article, a numerical study on the flow in a multistage, mixed-type electric submersible pump (ESP) is presented, where the authors evaluate the influence of turbulence models and the number of stages on performance.

61 citations

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TL;DR: In this paper, a dual-modality measuring technique is introduced which may be well applied for three-phase flow visualization, based on simultaneous excitation with two distinct frequencies to interrogate each crossing point of a mesh sensor, which is linked to conductive and capacitive parts of fluid impedance.
Abstract: Three-phase gas–liquid–liquid flows are very common in petroleum extraction, production, and transport. In this work a dual-modality measuring technique is introduced which may be well applied for three-phase flow visualization. The measuring principle is based on simultaneous excitation with two distinct frequencies to interrogate each crossing point of a mesh sensor, which in turn are linked to conductive and capacitive parts of fluid impedance. The developed system can operate eight transmitter and eight receiver electrodes at a frame repetition frequency up to 781 Hz. The system has been evaluated by measuring reference components. The overall measurement uncertainty was 8.4%, which considering the fast repetition frequency of measurements is suitable for flow investigation. Furthermore, a model-based method to fuse the data from the dual-modality wire-mesh sensor and to obtain individual phase fraction of gas–oil–water flow is introduced. Here a parametrized model is fitted to the measured conductivity and permittivity distributions enabling one to obtain phase fraction from measured data. The method has been applied and tested to the acquired data from a mesh sensor in static and dynamic three-phase mixtures of gas, oil, and water. Fused images and quantitative values show good agreement with reference values. The newly developed dual-modality wire-mesh sensor has the potential to investigate three-phase flows to a good degree of detail, being a valuable tool to investigate such flows.

42 citations

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TL;DR: In this paper, a two-stage centrifugal pump with radial-type impellers and a vaned diffuser was used for head evaluation and high-speed flow visualization, where the first stage impeller was replaced by equivalent pieces reproduced with great fidelity using a transparent material.

38 citations


Cited by
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Journal ArticleDOI
TL;DR: This review summarizes the different properties of gas hydrates as well as their formation and dissociation kinetics and then reviews the fast-growing literature reporting their role and applications in the aforementioned fields, mainly concentrating on advances during the last decade.
Abstract: Gas hydrates have received considerable attention due to their important role in flow assurance for the oil and gas industry, their extensive natural occurrence on Earth and extraterrestrial planets, and their significant applications in sustainable technologies including but not limited to gas and energy storage, gas separation, and water desalination Given not only their inherent structural flexibility depending on the type of guest gas molecules and formation conditions, but also the synthetic effects of a wide range of chemical additives on their properties, these variabilities could be exploited to optimise the role of gas hydrates This includes increasing their industrial applications, understanding and utilising their role in Nature, identifying potential methods for safely extracting natural gases stored in naturally occurring hydrates within the Earth, and for developing green technologies This review summarizes the different properties of gas hydrates as well as their formation and dissociation kinetics and then reviews the fast-growing literature reporting their role and applications in the aforementioned fields, mainly concentrating on advances during the last decade Challenges, limitations, and future perspectives of each field are briefly discussed The overall objective of this review is to provide readers with an extensive overview of gas hydrates that we hope will stimulate further work on this riveting field

349 citations

01 Jan 2003
TL;DR: In this article, the formation of porous gas hydrates from deuterated ice Ih powders was examined by electron microscopy and found to have a submicron porous structure.
Abstract: Gas hydrates grown at gas−ice interfaces were examined by electron microscopy and found to have a submicron porous structure. In situ observations of the formation of porous CH4- and CO2-gas hydrates from deuterated ice Ih powders were made, using time-resolved neutron diffraction on the high-flux diffractometer D20 (ILL, Grenoble) at different pressures and temperatures. For the first time neutron diffraction experiments were also performed with methane in hydrogenated samples. The isotopic differences between H2O and D2O are found insignificant concerning the clathrate formation kinetics. At similar excess fugacities, the reaction of CO2 was distinctly faster than that of CH4. The transient formation of the CO2-hydrate crystal structure II was also observed in coexistence with the usual type-I hydrate reaching a maximum of 5% after 5 h of the reaction at 272 K. A phenomenological model for the kinetics of the gas hydrate formation from ice powders is developed with special account of sample consolidatio...

206 citations

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TL;DR: In this paper, a viscous fluid flowing past a rotating isothermal cylinder with heat transfer is studied and simulated numerically by the lattice Boltzmann method (LBM), and a numerical strategy for dealing with curved and moving boundaries of second-order accuracy for both velocity and temperature fields is proposed and presented.

189 citations